Drying of fabrics



June 28, 1966 F. cATALLO 3,257,735

DRYING OF FABRICS Filed March 7, 1963 5 Sheets-Sheet l FIG. I

VARIABLE DRIVE INVENTOR. FRANK CATALLO BY ATTORNEYS June 28, 1966 F. CATALLO 3,257,735

DRYING 0F FABRICS Filed March 7, 1963 3 Sheets-Sheet 2 FIG. 3

F L as L l A, 34 35 A I I 3| A m as 27 I k L1 6lo-- k 600 INVENTOR. 6 FRANK CATALLO ATTORNE June 28, 1966 F. CATALLO DRYING OF FABRICS 3 Sheets-Sheet 5 Filed March 7, 1963 INVENTO FRANK CATA ATTORNEYS United States Patent York 7 Filed Mar. 7, 1963, Ser. No. 263,484 10 Claims. (Cl. 34--21) The present invention relates to the treatment of fabrics, and more particularly to improved method and means for drying and treating tubular knitted fabrics. Although the invention is not thus limited, it is particularly advantageous in connection with the drying and treating of tubular knit wool fabrics, where it is advantageous to maintain the fabric under tension during the treatment.

In connection with the drying of fabrics, such as tubular knit goods, it has been proposed heretofore to convey tubular material through a treatment zone, in which the material is expanded to form a tube and air is directed into the interior of the tube at one area and caused to flow out of the tube at another area, the air thus flowing picking up moisture from the fabric and carrying the moisture away to be exhausted, precipitated, etc. The present invention involves the treatment of tubular fabric in this known, general way, but ina manner which is novel and substantially improved in several more specific respects, all to the end that the drying and treating of tubular knitted fabric may be carried out more expeditiously and with substantially greater efficiency.

In accordance with one aspect of the invention, tubular knit fabric is conveyed through a treating zone, in which the material is expanded to form a hollow tube, the treating zone being divided into smaller zones which, for ease ofreference, may be referred to herein aspreheating, drying, and post-heating zones. The drying zone is located between the pre-heating and post-heating zones and contains air under pressure which is caused to flow radially into the tube of material as it is con: veyed through the treating zone. The air thus entering the tube of fabric is caused to flow axially in both directions, and is caused to flow out of the fabric in the preheating and post-heating zones. The improved arrangement results in a superior and more efficient drying of the material and also provides for an advantageous ballooning of the fabric tube on both sides of the drying zone.

In accordance with one of the more specific aspects of the invention, the material being conveyed through the drying zone is subjected to the action of discrete, relatively high velocity streams of air directed generally normal to the surface of the material so as to pass readily through the walls of the tube. In the pre-heating and post-heating zones, however, the air is allowed to flow generally uniformly out through the walls of the fabric, over the entire surface thereof exposed in the zones. Advantageously, the fabric tube is substantially closed at the outer ends of the pre-heating and post-heating zones, so that these zones have rather finite limits.

The method and apparatus of the invention are particularly useful in connection with the drying and treating of tubular knit Woolen fabrics, where it is desired to maintain the woolen fabric under longitudinal tension during the treating procedure. To this end, the apparatus of the invention incorporates controllably driven means, in front of and behind the drying zone, for advancing the fabric on opposite sides of the drying zone at independently controllable speeds. Most advantageously, the advancing means comprises pairs of sealing rollers serving to close off the outer ends of the preheating and post-heating zones and also having driving engagement with the fabric tube substantially across its ice width. The pairs of sealing rollers are connected for variable speed operation, relative to each other, so that the exit side rollers may be driven at a slightly higher speed than the entry side rollers, for example, to place the fabric tube under desired longitudinal tension.

In the improved apparatus, the treating zone is formed by a housing, which is divided by walls or baflies to form the pre-heating, drying, and post-heating zones, as described. A spreader extends throughout the treating zone and, advantageously, projects outwardly of each end thereof. The tubular fabric conveyed toward the treating zone may be in rope or flat form and is opened out to form an expanded tube as the fabric enters the pre-heating zone. The tube is maintained in an open condition substantially throughout the entire treating zone but advantageously is closed at the entry and exit sides of the zone.

The above and other advantageous features of the invention may be better understood upon reference to the following detailed specification and to the accompanying drawing, in which:

FIG. 1 is a longitudinal, cross-sectional view of a treating apparatus incorporating features of the invention and adapted especially for carrying out the new method;

FIGS. 2 and .3 are cross-sectional views taken generally along lines 22, 33 of FIG. 1;

FIG. 4 is a perspective view of a fabric spreading device incorporated in the apparatus of FIG. 1; and

FIG. 5 is a perspective view of an alternative form of spreading device which may be incorporated in the new apparatus.

In accordance with the invention, tubular fabric, such as tubular knitted wool fabric, which is usually though not necessarily in rope form, is conveyed successively through a pro-heating zone 10, a drying zone 11, and a post-heating zone 12, the zones Iii-12 collectively forming a treating zone. over a spreader 13 which opens up the fabric tube, forming an enlarged internal passage therein. The fabric tube passing through the drying zone 11 is subjected to the action of air under pressure, which causes streams of air to flow into the interior of the fabric, through the walls of the opened tube. The air thus directed into the interior of the tube flow-s generally axially, in both directions, into the portions of the tube lying within the preheating and post-heating zones 10, 12. In the zones 10, 12 the air pressure within the fabric tube is greater than that surrounding the tube, so that air flows outwardly through the walls of the tube and into the surrounding areas of the chamber.

As illustrated in FIG. 1, the fabric tube lying within the pre-heating and post-heating zones 10, 12 is unconfined, externally, and therefore tends to balloon out, as indicated at 14, 15, under the influence of the higher pressure air within the tube.

Advantageously, the fabric tube is substantially closed off at each end of the treating zone, so that substantially the entire volume of air entering the fabric tube within the drying zone 11 must pass out through the walls of the tube in the pre-heating and post-heating zones 10, 12. In addition, the zones 10, 12 are provided with outlet openings only at the ends so that air flowing into these zones, through the walls of the fabric tube, must flow in a generally axial direction, about the fabric tube, to reach the ends of the zone.

At least part of the air flowing out of the pre-heating and post-heating zones 10, 12 may be heated and recirculated through the fabric. The remaining portion of the air may be dispelled to the atmosphere through" suitable exhaust duct means. Advantageously, the respective portions of the air which are recirculated and exhausted Within the zone, the fabric is passed 0 may be varied to provide for maximum opera-ting efiiciency under a variety of circumstances.

The apparatus of the invention advantageously comprises a housing generally designated by the numeral 16, which is divided into upper and lower portions 17, 18 by horizontal baffle plates 19, 20. The housing 16 may be of generally rectangular form, and the upper portion thereof is closed by cover members 21, 22 hinged at 23, 24 to vertical walls 25, 26 of the housing structure. The upper portion 17 of the housing, in general, constitutes a treating zone and is divided by the vertical walls 25, 26 to form the pre-heating zone 10, drying zone 11 and post-heating zone 12.

Advantageously, the upper walls of the pre- .eating and post-heating zones 10, 12 are formed by baffle plates 27, 28 which extend generally horizontal and slightly downward from the vertical walls 25, 26 and which have downwardly curved outer end portions 29, 30 forming, in effect the ends of the respective chambers. The end portions 29, 30 of the bafiles are spaced inwardly from the end walls 31, 32 of the covers 21, 22 to provide passages into the spaces above the bafiles. These spaces communicate with openings 33 in the vertical walls 25, 26 leading into an exhaust duct 34. As shown in FIG. 3, the exhaust passages formed by the baflles 27, 28 are defined in part by internal vertical walls 35, 36, which converge toward the outlet openings 33 to provide for more efficient air flow. The outlet openings 33 may be adjustably restricted by means of sliding plates 37, and a fan 38 may also be provided in the exhaust duct 34 to provide further control over the quantities of air flowing through the exhaust system.

The heating chamber 11, which is located between the vertical walls 25, 26, is separated from the exhaust duct 34 by a horizontal plate 39, which extends substantially from one side to the other of the housing 16. The bottom of the chamber is substantially closed off by a plate 40, as shown in FIG. 2, an opening 41 being provided at one side, however, through which the chamber 11 is connected to the outlet of an air blower 42.

In accordance with one of the specific aspects of the invention, the chamber 11 is provided with a series of ring-like or tubular sections 43, which are of oval outline, as shown in FIG. 2, and which are of generally channelshaped cross-section, as shown in FIG. 1. The tubular members 43 are arranged in a series, in axial alignment, and extend, as a series, from one end to the other of the drying chamber. The individual tubular members 43 are spaced from each other, and the series thereof is supported by means of axially disposed structural elements 44. The arrangement is such that narrow spaces are defined between the flange portions 45 of the adjacent pairs of tubular members. These spaces form, in effect, nozzles through which air under pressure in the area surrounding the tubular members is discharged at relatively high velocity into the generally tubular open space formed by the series of members. Thus, when the outer portion of the chamber 11 is supplied with air under pressure by the blower 42, relatively high velocity streams of air of a more or less discrete nature are issued between pairs of tubular members.

As shown in FIG. 1, the lower portion 18 of the housing is divided by vertical walls 46, 47 and heater assemblies 48, 49 into three chambers. The end chambers are in communication with the pro-heating and post-heating chambers 10, 12, through openings 50, 51, while the central chamber is in communication with the inlet 52 of the air blower. The end chambers are also in communication with the center chamber through the heater assemblies 48, 49. Accordingly, when the blower 42 is in operation, air is drawn from the pre-heating and post-heating zones 14 12 into the end chambers, through the heaters 48, 49 and into the blower 42. In this manner, air drawn (from the zones 10, 12 is reheated and discharged into the drying zone 11.

The spreader 13 advantageously is of such length as to extend throughout the entire housing 16 and to project a short distance from each end of the housing. The spreader shown to be incorporated in the apparatus of FIG. 1 is illustrated in greater detail in FIG. 4 and is comprised of a pair of beamlike sections 53, 54 connected at their ends by adjustable spacers 55. The beam sections 53, 54 are of open construction and are relatively fiat at the ends while having center portions of substantially increased thickness. The beam sections may also be shaped to diverge progressively toward the outer ends thereof, whereby the assembled spreader structure has a substantially uniform girth throughout its length. At the opposite ends of each of the beam structures 53, 54 is a recessed journal block 56, in which are mounted rollers 57. Each journal block has a pair of the rollers 57, which are freely rotatable, and these rollers are adapted to be engaged by pairs of driven edge rolls 58, 59 located outside of the housing 16. The edge rolls 58, 59 are grooved to receive the rollers 57, so that the spreader structure may be supported and locked in position by the driven rollers.

As shown best in FIG. 1, the fiat end portions of the spreader 13 extend inward from the driven edge rolls 58, 59, substantially to the ends of the pre-heating and postheating chambers 10, 12. Mounted above and below the flat portions Otf the spreader, at each end, are pairs of driven sealing rollers 60a, 60b and 61a, 61b. The rollers 69b, 61b may be journaled in fixed positions on the housing structure, while the upper rollers 60a, 61a may be carried by the hinged covers 21, 22. Normally, when the covers 21, 22 are in the positions illustrated in full lines in FIG. 1 the sealing rollers 60, 61 are spaced apart a distance not substantially greater than the thickness of the spreader 13.

Advantageously, the driven sealing rollers are provided with spaced grooves or recesses for receiving the extending end portions of the spreader frame. Thus, the spreader frame is accommodated by the rollers, which are at the same time able to be brought substantially into contacting relation, in order to have gripping engagement with the fabric passing over the spreader frame. In accordance with one aspect of the invention, the rollers 60, 61 (as well as the driven edge rolls 58, 59) are arranged to be driven at controlled, related speeds, by a suitable variable drive mechanism indicated schematically in FIG. 1. The arrangement is such that the edge rolls 58 and sealing rolls 60 may be set to operate at a first predetermined speed, while the sealing rolls 61 and the edge rolls 59 may be set to operate at a slightly faster speed, for example, in order to maintain the fabric tube under a predetermined degree of longitudinal tension, where desired. This is particularly advantageous in connection with the processing of knitted woolen fabrics, for example.

In the operation of the apparatus, moist tubular fabric, which may be in rope form, is applied over the spreader 13, being engaged at its edges by the edge rolls 58, 59 and being passed between the pairs of driven sealing rollers 60, 61. Fabric is drawn through the apparatus by the rolls 58, 59, while air under pressure is supplied to the drying zone 11 by operation of the blower 42.

'As the fabric is conveyed through the housing 16, the tube is opened by the spreader 13, at least during its passage through the drying zone 11. Heated air under pressure is discharged in discrete, relatively high velocity streams, through the nozzles formed by the tubular sections 43, and passes through the Walls of the fabric tube, into the interior of the tube. Some of the moisture of the fabric is picked up by the air as it passes into the tube, as will be understood.

Air flowing into the fabric tube, in the drying zone 11, tends to flow axially in both directions, into the pre-heating and post-heating zones 10, 12. If desired, suitable adjustable bafiie means may be carried by the spreader frame, at spaced positions corresponding generally to the ends of the drying zone, to permit desired variation in the relative proportions of air flow into the pre-heating and post-heating zones.

Air flowing into the pre-heating zone balloons the fabric in the manner shown in FIG. 1 and passes outwardly through the walls of the tube, as illustrated. This serves to pre-heat the fabric approaching the drying zone driven sealing rollers 60a, 6% at the entry side of the apparatus effectively close the fabric tube and thereby substantially prevent the axial flow of air through the tube beyond the confines of the housing 16.

Air flowing axially within the tube toward the postheating chamber 12 causes ballooning of the fabric being conveyed through that chamber and passes through the walls of the fabric tube into the chamber area surrounding the fabric. The air then flows axially toward the end of the post-heating chamber and is divided for exhaust flow and recirculation flow in the manner before described. The air flowing forward in the post-heating chamber, through and about the tube of fabric, removes further moisture therefrom. The moisture-laden air is substantially prevented from escaping through the exit opening in the housing by the sealing rollers 61a, 6117.

In some cases it may be advantageous to use an alternative form of spreading device, as shown in FIG. 5. The alternative spreading device, generally designated by the reference numeral 70, is provided with means extending into the treating zone for propelling the fabric tube by its edges. The spreader 70 comprises a central body sec tion 71, which includes axially spaced, adjustable tubular forms 72, 73 of oval outline. The forms 72, 73 are mounted on a longitudinal frame member 74, which is of sufficient length to extend out of the housing 16 at both ends.

Mounted at the ends of the member 74 are cross braces 75, 76 which adjustably support pairs of longitudinally disposed arms 77, 78. The arms 77 at the entry end of the spreader are recessed at 77a to receive the grooved, driven edge rolls 58, idling roller 79 being provided to engage the driven rollers. The arms 77 are also provided with belts 80 which engage the edge rolls 58 and extend along the arms into the housing. A U-shaped opener 81 extends longitudinally from the arms 77 for initially open ing incoming material.

The arms 78 at the exit side of the frame are provided with recesses 82 for receiving the edge rolls 59, and belts '83, 84 extending in both longitudinal directions from the rolls are driven thereby.

Tubular fabric travelling over the spreader 70 is engaged at its edges by the belts 77, 83, 84, so that propelling force is applied to the fabric substantially throughout the length of the treating zone. The center por-tion'72 of the frame is positioned within the drying zone 11 of the housing and supports the material as it passes through that zone. The pairs of arms 77, 78 lie within the pre-heating and post-heating zones 10, 12, where the tube of material is ballooned by the out-flowing air.

The specific forms of spreaders shown in FIGS. 4 and 5 have been found to have specific advantages for certain frequently encountered operating conditions. However, it should be apparent that the new method may be carried out successfully with spreaders of other design.

The new method and apparatus are advantageous in that highly eflicient drying of tubular material may be carried out in a practical minimum of space. High efficiency in the drying of the material is realized by directing air into an opened tube of fabric intermediate the ends of a treating zone and causing the air to flow axially of I 6 the fabric, within the tube, and out through the walls of the tube in pre-heating and post-heating zones. The outflow of air through the fabric, in the pre-heating and post-heating zones, is particularly advantageous in that it results in a ballooning of the material, which imparts thereto desirable characteristics.

It should 'be understood that the method and apparatus herein specifically illustrated and described are intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

What is claimed is:

1. The method of drying and treating tubular knitted fabric, which comprises (a) conveying the fabric througha treating zone,

(b) opening the fabric tube within the treating zone by spreading the fabric internally over a substantial length,

(0) directing air in discrete relatively high velocity streams radially into the interior of the opened tube as the tube passes through a drying zone of limited length intermediate the ends of the treating zone,

(d) directing a first portion of the flow of air internally of the fabric tube from the drying zone toward the fabric entrance end of the treating zone and withdrawing the air generally and in a distributed manner through the walls of the tube to effect pre-heating of the fabric travelling toward the drying zone,

(e) directing a second portion of the flow of air internally of the fabric tube from the drying zone toward the fabric exit end of the treating zone and withdrawing the air generally and in a distributed manner through the walls of the tube to effect post-heating of the fabric, and

(f) maintaining the fabric tube substantially flat and closed adjacent the ends of the treating chamber and causing it to balloon within the pre-heating and postheating zones.

2. The method of claim 1, in which (a) air flowing out of the fabric tube in the pre-heating and post-heating zones is caused to flow about the fabric and axially toward the ends of the treating zone.

3. The method of claim 1, in which (a) the fabric tube is flattened and substantially closed adjacent the ends of the treating chamber by being caused to pass between sets of rollers.

4. Apparatus for drying tubular knitted fabric, comprising (a) means forming an enclosed treating zone,

(b) means intermediate the ends of the treating zone forming a drying zone of limited lengthand dividing the treating zone to form pre-heating and postheating zones on opposite sides of the drying zone,

(c) means for spreading open the fabric tube within the drying zone,

((1) means for directing air in discrete relatively high velocity streams into the fabric tube within the drying zone,

(e) means for Withdrawing air generally and in a dis tributed manner from the tube in the pre-heating and post-heating zones, and

(f) means at each end of the treating zone defining entrance and exit openings of limited size for the" fabric. 5. The apparatus of claim 4, in which. (a) the means for spreading extends throughout the treating zone, and (b) portions of the spreading means project outward from the ends of the zone.

6. The apparatus of claim 4, in which (a) the drying zone comprises spaced entry-side and exit-side end walls and a tubular structure extending axially between the end Walls and forming a tubular passage,

(b) the tubular structure being of a size to accommodate the axial passage therethrough of the fabric tube.

7. The apparatus of claim 6, in which (a) the tubular structure is comprised of a plurality of axially disposed tubular sections of short axial length,

(b) the sections being substantially imperforate and being positioned axially end to end with predetermined axial spaces therebetween forming slots for the discharge of air radially inward in discrete, relatively high velocity streams.

8. The apparatus of claim 6, in which (a) the treating zone comprises a substantially enclosed chamber having air outlet openings adjacent each end, and

(b) a blower is arranged with its outlet in communication with the drying chamber and with its inlet in communciation with the chamber outlet openings,

(c) said outlet openings being small in relation to the length of said pre-heating and post-heating zones, whereby air is caused to flow longitudinally over the exterior of the fabric tube in said zones.

9. The apparatus of claim 4, in which (a) the spreading means includes means on opposite sides of said drying zone for engaging the fabric tube, and

(b) variable drive means are provided for the fabric engaging means,

(c) whereby the fabric tube may be maintained under predetermined longitudinal tension during drying.

10. The apparatus of claim 9, in which (a) the fabric engaging means comprise pairs of driven rollers,

(b) said rollers engaging the fabric tube at the ends of the treating zone and serving additionally to close the tube.

References Cited by the Examiner UNITED STATES PATENTS WILLIAM F. ODEA, Primary Examiner. NORMAN YUDKOFF, Examiner. I. SOFER, Assistant Examiner. 

1. THE METHOD OF DRYING AND TREATING TUBULAR KNITTED FABRIC, WHICH COMPRISES (A) CONVEYING THE FABRIC THROUGH A TREATING ZONE, (B) OPENING THE FABRIC TUBE WITHIN THE TREATING ZONE BY SPREADING THE FABRIC INTERNALLY OVER A SUBSTANTIAL LENGTH, (C) DIRECTING AIR IN DISCRETE RELATIVELY HIGH VELOCITY STREAMS RADIALLY INTO THE INTERIOR OF THE OPENED TUBE AS THE TUBES PASSES THROUGH A DRYING ZONE OF LIMITED LENGTH INTERMEDIATE THE ENDS OF THE TREATING ZONE, (D) DIRECTING A FIRST PORTION OF THE FLOW OF AIR INTERNALLY OF THE FABRIC TUBE FROM THE DRYING ZONE TOWARD THE FABRIC ENTRANCE END OF THE TREATING ZONE AND WITHDRAWING THE AIR GENERALLY AND IN A DISTRIBUTED MANNER THROUGH THE WALLS OF THE TUBE TO EFFECT PRE-HEATING OF THE FABRIC TRAVELLING TOWARD THE DRYING ZONE, (E) DIRECTING A SECOND PORTION OF THE FLOW OF AIR INTERNALLY OF THE FABRIC TUBE FROM THE DRYING ZONE TOWARD THE FABRIC EXIT END OF THE TREATING ZONE AND WITHDRAWING THE AIR GENERALLY AND IN A DISTRIBUTED MANNER THROUGH THE WALLS OF THE TUBE TO EFFECT POST-HEATING OF THE FABRIC, AND (F) MAINTAINING THE FABRIC TUBE SUBSTANTIALLY FLAT AND CLOSED ADJACENT THE ENDS OF THE TREATING CHAMBER AND CAUSING IT TO BALLOON WITHIN THE PRE-HEATING AND POSTHEATING ZONES. 